412 



AKTEEIES OF THE UPPER LIMB. 



the annular ligament, arc given off from the upper or concave side of 

 the palmar arch. 



(r) The digital branches, usually four in numl^er, proceed downwards 

 from the convexity of the palmar arch to supply both sides of the three 

 inner fingers, and the ulnar side of the fore finger. Tiie first dir/ifal 

 branch inclines inwards to the ulnar border of the hand, and, after giving^ 

 minute offsets to the muscles of the little finger, runs along the inner 

 margin of its phalanges. The secoiul runs along the fourth metacarpal 

 space, and at the root of the fingers divides into two branches, which 

 ])roceed along the contiguous borders of the ring and little fingers. The 

 third is similarly distributed to the riug and middle fingers ; and the 

 fonrtlt to the latter and the index fingers. The thumb and the radial 

 side of the index finger are sup[)lied from the i-adial artery. 



Fig. 2f)9. — SUPKHFICIAL DrSSECTIOX OF THE LOWKK 



Part of the Fuukakm and the Hand, show- 

 ing THK Uamal ani> Ulnau Akteuies, the 

 Superficial Palmar Arch, and the accom- 

 I'ANViNG Nerves (from R. Quain). I 



a, i)lacei;l on the deep fascia of tlie forearm, be- 

 tween tlie tendons of the palmaris loiigus and flexor 

 carpi radialis muscles ; h, points by a line crossing 

 the pisiform bone to the ulnar nerve ; r, points to the 

 styloid x>rocess of tiie radius and twigs of the radial 

 nerve ; 1, radial artery lying on the flexor longus. 

 pollicis ; 1', the radial artery passing behind the 

 tendons of the extensor ossis metacarpi pollicis. 

 and extensor primiinternodii pollicis ; 2, supcrticialis 

 voke branch piercing the short muscles of the thumb 

 and emei-ging below to join the superficial palmar 

 arch ; 3, external branch of the princeps pollicis ; 4, 

 radialis indicis ; a branch from the superficial arch 

 is seen joining the internal branch of the princeps 

 pollicis ; 5, ulnar artery lying upon the flexor digi- 

 torum profundus ; fi', the same descending on the 

 anterior aiuiular ligament to form the superficial 

 palmar arch ; 6, deep Ijranch of the ulnar artery 

 passing between the abductor and flexor minimi 

 digiti to join the deep arch, accompanied by the deep 

 branch of the ulnar nerve ; 7, branch of the super- 

 ficial arch to the ulnar side of the little finger ; S, 

 division of the common branch to the 4th and 5th 

 fingers ; 9, the same to the 3rd and 4tli fingers ; 10, 

 the same to the 2nd and 3rd fingers ; 7 and 8, are 

 accompanied by the digital branches of the ulnar 

 nerve, and 3, 4, 9, and 10, by the branches of the 

 median nerve. 



The digital arteries are placed at first 

 superficial to the tendons, and then they lie 

 between them, accompanied by the digital 

 nerves as far as ^ne clefts of the fingers, where they are joined by the 

 anterior interosseous arteries, l)ranches of the deep arch. On the sides 

 of the fingers, each artery lies beneath the corres])onding nerve, and 

 gives branches which supply the sheaths of the tendons and the joints, 

 some of them anastomosing across the front of the bones with similar 

 branches from tlic opposite side. At about the middle of the last 

 phalanx, tlie two branches for each finger converge and form an arch, 



